This research proposal describes the design and development of an efficient and flexible route to the immunological adjuvant, QS-21A. The synthesis of QS-21A and any analogs would advance their development as possible vaccine additives that could in turn help prevent a variety of diseases including cancer, AIDS, and malaria. The synthesis highlights novel methodology of glycosidic coupling, involving one-pot glycoslyations with 1-hydroxy glycosyl donors. The successful use of this methodology in a complex synthesis would expand the tools chemists may employ to construct biologically-important polysaccharides like the components of QS-21A.